We found that while most VTA VGluT2 neurons decreased their firing rates during sucrose consumption, a few VTA VGluT2 neurons increased their firing rates. We also found that while the firing rates of some VTA VGluT2 neurons changed only by the presence of the delivered reward, the firing rates of others were not affected by the presence or omission of the reward. Regarding responses by VTA VGluT2 neurons to the aversive stimulus, we found that the firing rates of most VTA VGluT2 neurons increased in response to airpuff, including those neurons whose firing rates were increased in response to sucrose reward. Based on our results from single cell in vivo recordings, we conclude that VTA VGluT2 neurons are heterogeneous in their function. We suggest that under physiological conditions, whereas most VTA VGluT2 neurons signal aversion, some VTA VGluT2 neurons signal salient stimuli.